Collapse Transformations and Continuously Raster problem

Hi,

Can someone please help?

Hope i can explain this properly. I have attached 3 screen grabs to try and show problems I am encountering.

Example_1 shows a character designed in illustrator that I am rigging and animating in AE. There are several layers that make up the character which works just how I want it to in this particular comp. I have also duplicated all layers and pre-comped these layers to create the shadow for the character. I have added a levels effect to darken it, I then gave it a slight blur and opacity and rotated on its side to give the effect of the shadow so that it follows the animation of the character in time with its movement.

Example_2 shows the character that has been brought into a new composition with the running track. This image shows the comp before collapse transform switch has been enabled and although prob hard to see on the image, it is blurred and not too clear.

Example_3 Shows the comp with collapse Transform switch enabled and although it makes the comp crisp and sharp as I want it to, 3 problems occur.

The first 2 problems are that the back leg and back arm move slightly further back than they are meant to. The shadow also changes slightly and where I masked off some of the shadow in the main comp so that it didnt cover the hand has now come back to cover it.

Hope this makes sense. I have read up on the render order and collapse transform switch but strugglin to get my head round it and its really buggin me why this is occurring. I would really appreciate some help with solving this?

Thanks

Scott

Thanks Roland,
The reason I would prefer to pre comp the footage is because there are going to be another 7 runners added to the scene and it's going to be a pain to manage with so many layers. I presumed this is what pre-comping was used for. Just buggin the hell out of me why it's doing what it's doing. As regards to 3D lights, I did try this but have to admit ive not had too much experience with using the lights and didn't look right. I applied the cast shadows to it but it didn't cast the floor shadows of the runner. Should I be using more than one light?
Thanks for your help
Scott

Thanks Walter,

I really thought that one of the main purposes of pre-comping was to help manage work flow like this particular example. I have seen several tutorials where it is done for this reason.

As far as Im aware, I havent done anything too complicated in my original comp. There is some parenting of layers, postion and rotation keyframes so I not sure why its causing the problem.

May it be a layer order stacking problem? I have read about the render order and that the way certain effects and tranformatioms are added can cause some problems. Dont understand how this would be the cause though as I've not added any effects to the main character, just transformations so am stuck as to what the cause is.

Thanks

Scott


Thanks for your response.

Regardless of whether you use precomps or not, your main problem is with Collapse Transformations. In most cases you don't want to use it since it changes the AE render order. It causes transformations of the subcomp (transforms applied to the subcomp layer inside the main comp) to be applied to the layers inside the subcomp before effects and masks inside the subcomp.

For your type of project you can really only use Coll Trans if you don't use any masks or effects at all to either the layers inside the subcomp or the subcomp itself. (at least not without causing massive grief)

If you keep everything in one comp like the others have suggested you can use Cont Rast on the Illustrator layers so long as you realize any effects on these layers will render after transforms. This is reverse of how it normally is. It will also render masks after transformations which makes them hard to use.

I have done quite a few project of somewhat similar nature to what you're doing, and this is my method:

I use subcomps like you do. I make the subcomp about twice as big as it needs to be (or more). This means in the main comp I scale it down, and I can move it around and scale it up/down a bit while remaining sharp.
If you use Illustrator layers, scale the layers up so they fit this larger subcomp, and enable Cont Rast. This will make them sharp inside the subcomp. DON'T enable Coll Trans on the subcomp itself.
With this technique you can also add effects to the subcomp without running into trouble. You can also use adjustment layers and whatever else inside the subcomp.

For shadow, duplicate the subcomp layer inside the main comp, and use the second comp for shadow. You can then add tint effects, blur, and so on.
Or use 3D to cast shadows.

The general rule is: Don't use Collapse Transformations on subcomps unless you have a very good reason. If you must, there are severe limitations you have to be aware of.

Bit of a long explanation, but hope it helps.

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http://www.jonbagge.net
Jon Bagge - Editor - London, UK
Avid - FCP - After Effects